We went to Kauai years ago. Every morning we were up by 5 or 5:30, ate breakfast on the lanai, then a 4 hour session at one of the spots while she sat on the beach and read or beachcombed. Done by 10, then sightseeing and back in time for an evening session most evenings. Finished the day with a nice dinner at a local restaurant, followed by an hour in the hot tub and then bed. A great, great trip (made even better because it was free - my wife exceeded her sales goals and this was her/our reward).